melanotic schwannoma
melanotic schwannoma
A rare form of schwannoma characterised by heavy deposition of melanin pigment (Fontana-Masson, S-100, HMB-45, all +ve) linked to melanosomes and premelanosomes. It is often (50% of cases) associated with Carney syndrome (myxomas in various sites, spotty pigmentation, endocrine hyperactivity).Prognosis
Most melanotic schwannomas behave benignly; they may metastasise.